Cam operated valves with minimum vent features have long been known. Several types are exemplified in U.S. Pat. Nos. 6,367,775 and 5,836,352. These valves are typically connected to the end of a product delivery hose and are operated manually in the transfer of gaseous or liquid products. The cam operated open and close feature provides fast operation without the repetitive motion found in the operation of a typical valve closure utilizing a threaded stem operated by a hand wheel. The hand wheel requires the operator to engage in a repetitive twisting wrist motion which may lead to repetitive motion injury.
Most cam operated valves still require a repetitive twisting motion to repeatedly connect the valve to the receiving or dispensing container. The thread engagement is typically only 4 threads, but since the connection operation is done with one hand it takes about three twists to get one rotation of the connector, so that the operator is subjected to at least 12 twisting motions to connect the device and another 12 twisting motions to disconnect the device. In the case of filling propane cylinders, for example, one operator may be asked to fill 50 or more cylinders in a day. Accordingly, the operator's wrist is subjected to 1,200 twisting motions which may lead to repetitive motion injury.
The present invention addresses the repetitive motion connection problem with a valve that uses cam operation and minimum vent features to provide a safe and quick connection feature that eliminates repetitive motion.
The disadvantages of the prior art are overcome by the present invention, and an improved cam operated valve is hereinafter disclosed.